In May 2004, the Company adopted its 2004 Equity Incentive Plan (“2004 Plan”), which replaced its 2000 Omnibus Equity Incentive Plan (“2000 Plan”). The 2000 Plan had allowed for the award of up to 11,500,000 shares of Class A common stock. The 2004 Plan, as originally adopted, allowed for the award of up to 10,000,000 shares of Class A common stock, plus any grants remaining available at its adoption date under the 2000 Plan. Awards under the 2004 Plan may be in the form of incentive stock options, nonqualified stock options, stock appreciation rights, restricted stock or restricted stock units. The 2004 Plan is administered by a committee appointed by the Board. This committee determines the type, number, vesting requirements and other features and conditions of such awards. Generally, stock options granted from the 2000 Plan have a contractual term of ten years from the date of the grant and vest over four or five years and stock options granted from the 2004 Plan have a contractual term of ten years from the date of the grant and vest over four years.

The 2004 Plan was amended by the Compensation Committee effective July 13, 2006 to (i) eliminate automatic option grants for non-employee directors, making any grants to such directors discretionary by the Compensation Committee and (ii) eliminate the three-year minimum vesting period for performance-based restricted stock and restricted stock units, making the vesting period for such grants discretionary by the Compensation Committee.

The 2004 Plan was further amended by the Board of Directors on April 28, 2014, and approved by the stockholders at the 2014 annual meeting of stockholders on May 29, 2014, to extend the term of the 2004 Plan until May 29, 2024.

The 2004 Plan was further amended by the Board of Directors effective April 29, 2021, and approved by the stockholders at the 2021 annual meeting of stockholders on May 27, 2021, to increase the number of shares of Class A common stock issuable under the 2004 Plan by 8,000,000 shares, for a total of 18,000,000 shares issuable thereunder.

The Company has issued stock options and restricted stock units to various employees and non-employee directors of the Company in addition to non-employee service providers under both the 2004 Plan and the 2000 Plan. As of December 31, 2022, there were approximately 6.2 million securities remaining available for future issuance under equity compensation plans.

The fair value of each stock option is estimated on the date of grant using the Black-Scholes option pricing model. Stock-based compensation expense related to stock options is based on the fair value on the date of grant and is amortized over the vesting period, generally between 1 to 4 years. Expected volatilities are based on historical volatility of the Company’s stock. The Company uses historical data to estimate option exercise and employee termination within the valuation model. The expected term of stock options granted is based on historical contractual life and the vesting data of the stock options. The risk-free rate for periods within the contractual life of the stock option is based on the U.S. Treasury yield curve in effect at the time of grant.

There were no stock options granted during the years ended December 31, 2022, 2021, and 2020.

The following is a summary of stock option activity: (in thousands, except exercise price data and contractual life data):


Options	Number of Shares			Weighted-Average Exercise Price		Weighted-Average Remaining Contractual Life (Years)		Aggregate Intrinsic Value
Outstanding at December 31, 2019		944		$	2.20			$	627
Exercised		(10	)		1.92				11
Forfeited or cancelled		(50	)		2.87
Outstanding at December 31, 2020		884			2.17				722
Exercised		(533	)		2.09				1,559
Forfeited or cancelled		-			-
Outstanding at December 31, 2021		351			2.28				1,577
Exercised		(91	)		1.71				381
Forfeited or cancelled		-			-
Outstanding at December 31, 2022		260			2.48		0.19		605
Vested and Exercisable at December 31, 2022		260			2.48		0.19		605

There was no stock-based compensation expense related to the Company’s employee stock options for the years ended December 31, 2022, 2021 and 2020.

The following is a summary of non-vested restricted stock and restricted stock units activity: (in thousands, except grant date fair value data):


	Number of Shares			Weighted-Average Grant Date Fair Value
Nonvested balance at December 31, 2019		2,256		$	3.64
Granted		2,623			2.96
Vested		(1,427	)		3.63
Forfeited or cancelled		(81	)		3.15
Nonvested balance at December 31, 2020		3,371			3.12
Granted		3,200			6.49
Vested		(1,926	)		4.35
Forfeited or cancelled		(115	)		3.03
Nonvested balance at December 31, 2021		4,530			5.00
Granted		3,555			5.43
Vested		(3,491	)		5.10
Forfeited or cancelled		(151	)		5.35
Nonvested balance at December 31, 2022		4,443			5.26

Stock-based compensation expense related to grants of restricted stock and restricted stock units was $20.0 million, $9.6 million and $5.1 million for the years ended December 31, 2022, 2021 and 2020, respectively.

As of December 31, 2022, there was approximately $13.0 million of total unrecognized compensation expense related to grants of restricted stock and restricted stock units that is expected to be recognized over a weighted-average period of 1.8 years.

The fair value of shares vested related to grants of restricted stock and restricted stock units was $18.1 million, $8.7 million, and $5.5 million for the years ended December 31, 2022, 2021 and 2020, respectively.

The Company’s restricted stock units are net settled by withholding shares of the Company’s common stock to cover minimum statutory incomes taxes and remitting the remaining shares of the Company’s common stock to an individual’s brokerage account. Authorized shares of the Company’s common stock are used to settle restricted stock units.